Measure 3D model dimensions online

Check the exact size, volume, surface area, and triangle count of any STL, OBJ, GLB, 3MF, or STEP file. Free, in your browser.

Measure the attached model: dimensions, volume, surface area, triangle count

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How to check STL dimensions online

Attach any STL, OBJ, PLY, GLB, 3MF, or STEP file and you'll instantly see its bounding box (X × Y × Z), solid volume, surface area, triangle and vertex counts, plus whether the mesh is watertight. STL files have no units, so this tool assumes millimeters (the 3D printing standard) and also shows the size in inches.

The volume readout is what you need for material estimates: pair it with the STL weight calculator to convert volume into grams of filament and cost.

Frequently asked questions

Why does my STL import at the wrong size?

STL stores raw numbers with no unit. Most software writes millimeters, but some CAD tools export inches, which leaves the model 25.4× too small or too large. If the dimensions here look off by exactly that factor, run the file through the scale tool with the inches to mm preset.

Is the volume accurate for open meshes?

Volume is computed exactly for watertight meshes. If the mesh has holes or non-manifold edges the number is an approximation, and the tool flags this. Repair the mesh first for an exact figure.

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